Station-Centric Multi-User Multiple Input Multiple Output (mu-Mimo)

1. A first apparatus for wireless communications, comprising: a processing system configured to determine a media access control (MAC) address of the first apparatus; and a transmitter configured to: transmit a multi-user (MU) packet to one or more second apparatuses, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the one or more second apparatuses belong; and transmit an indication of the MAC address of the first apparatus to the one or more second apparatuses for interpretation of the group ID, wherein the transmitter is configured to transmit the indication of the MAC address in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble.

2. The first apparatus of claim 1 , wherein the frame comprises, for at least one of the one or more second apparatuses associated with the group ID: an indication of a number of spatial streams; and an indication of an association identifier (AID) or an indication of a multi-user identifier (MID) assigned by the first apparatus if a direct link is established between the first apparatus and the at least one of the one or more second apparatuses.

3. The first apparatus of claim 1 , wherein the frame comprises an indication of a temporary group ID indicating the group to which the one or more second apparatuses belong for the MU packet.

4. The first apparatus of claim 1 , wherein the frame is a redefined null data packet announcement (NDPA) frame, and wherein a bit in a sounding sequence field of the redefined NDPA frame indicates that the frame is not a conventional NDPA frame.

5. The first apparatus of claim 1 , wherein the frame comprises an indication of a MAC address for each of the one or more second apparatuses associated with the group ID.

6. A method for wireless communications, comprising: determining a media access control (MAC) address of a first apparatus; transmitting a multi-user (MU) packet to one or more second apparatuses, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the one or more second apparatuses belong; and transmitting an indication of the MAC address of the first apparatus to the one or more second apparatuses for interpretation of the group ID, wherein transmitting the indication of the MAC address comprises transmitting the indication of the MAC address in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble.

7. The method of claim 6 , wherein the frame comprises, for at least one of the one or more second apparatuses associated with the group ID: an indication of a number of spatial streams; and an indication of an association identifier (AID) or an indication of a multi-user identifier (MID) assigned by the first apparatus if a direct link is established between the first apparatus and the at least one of the one or more second apparatuses.

8. The method of claim 6 , wherein the frame comprises an indication of a temporary group ID indicating the group to which the one or more second apparatuses belong for the MU packet.

9. The method of claim 6 , wherein the frame is a redefined null data packet announcement (NDPA) frame, and wherein a bit in a sounding sequence field of the redefined NDPA frame indicates that the frame is not a conventional NDPA frame.

10. The method of claim 6 , wherein the frame comprises an indication of a MAC address for each of the one or more second apparatuses associated with the group ID.

11. A first apparatus for wireless communications, comprising: means for determining a media access control (MAC) address of the first apparatus; and means for transmitting a multi-user (MU) packet to one or more second apparatuses, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the one or more second apparatuses belong and wherein the means for transmitting is also configured to transmit an indication of the MAC address of the first apparatus to the one or more second apparatuses for interpretation of the group ID, wherein the means for transmitting is configured to transmit the indication of the MAC address in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble.

12. The first apparatus of claim 11 , wherein the frame comprises, for at least one of the one or more second apparatuses associated with the group ID: an indication of a number of spatial streams; and an indication of an association identifier (AID) or an indication of a multi-user identifier (MID) assigned by the first apparatus if a direct link is established between the first apparatus and the at least one of the one or more second apparatuses.

13. The first apparatus of claim 11 , wherein the frame comprises an indication of a temporary group ID indicating the group to which the one or more second apparatuses belong for the MU packet.

14. The first apparatus of claim 11 , wherein the frame is a redefined null data packet announcement (NDP A) frame, and wherein a bit in a sounding sequence field of the redefined NDP A frame indicates that the frame is not a conventional NDP A frame.

15. The first apparatus of claim 11 , wherein the frame comprises an indication of a MAC address for each of the one or more second apparatuses associated with the group ID.

16. A non-transitory computer-readable medium comprising instructions executable to: determine a media access control (MAC) address of a first apparatus; transmit a multi-user (MU) packet to one or more second apparatuses, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the one or more second apparatuses belong; and transmit an indication of the MAC address of the first apparatus to the one or more second apparatuses for interpretation of the group ID, wherein the indication of the MAC address is transmitted in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble.

17. A wireless node, comprising: at least one antenna; a processing system configured to determine a media access control (MAC) address of the wireless node; and a transmitter configured to: transmit, via the at least one antenna, a multi-user (MU) packet to one or more apparatuses, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the one or more apparatuses belong; and transmit, via the at least one antenna, an indication of the MAC address of the wireless node to the one or more apparatuses for interpretation of the group ID, wherein the indication of the MAC address is transmitted in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble.

18. A first apparatus for wireless communications, comprising: a receiver configured to: receive a multi-user (MU) packet from a second apparatus, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the first apparatus belongs; and receive an indication of a media access control (MAC) address of the second apparatus, wherein the indication of the MAC address of the second apparatus is received in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble; and a processing system configured to interpret the group ID based on the MAC address.

19. The first apparatus of claim 18 , wherein the processing system is configured to interpret the group ID by determining that the MAC address is associated with the second apparatus, such that the MU packet was transmitted by the second apparatus and the group ID is associated with the second apparatus.

20. The first apparatus of claim 18 , wherein the receiver is configured to receive a message from the second apparatus, the message indicating assignment of the first apparatus to the group and indicating, for the group ID, a spatial stream associated with the first apparatus in MU packets to be transmitted to the group from the second apparatus.

21. The first apparatus of claim 20 , further comprising decoding the MU packet using the spatial stream associated with the group ID for the first apparatus.

22. The first apparatus of claim 20 , wherein the processing system is further configured to consider the assignment of the first apparatus to the group as being valid for at most a duration of the MU packet or until a gap occurs that is longer than a point coordination function (PCF) interframe space (PIFS).

23. The first apparatus of claim 18 , wherein the receiver is further configured to receive another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs, wherein the other MU packet is not immediately preceded by another frame with another MAC address, and wherein the processing system is configured to: determine that the other MU packet was transmitted by an access point (AP); and interpret the other group ID as assigned by the AP.

24. The first apparatus of claim 18 , wherein the receiver is further configured to: receive another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs; and receive an indication of a Basic Service Set Identifier (BSSID) in another frame received prior to the other MU packet, wherein the processing system is configured to interpret the other group ID based on the BSSID.

25. A method for wireless communications, comprising: receiving, at a first apparatus, a multi-user (MU) packet from a second apparatus, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the first apparatus belongs; receiving an indication of a media access control (MAC) address of the second apparatus, wherein the indication of the MAC address of the second apparatus is received in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble; and interpreting the group ID based on the MAC address.

26. The method of claim 25 , wherein the interpreting comprises interpreting the group ID by determining that the MAC address is associated with the second apparatus, such that the MU packet was transmitted by the second apparatus and the group ID is associated with the second apparatus.

27. The method of claim 25 , further comprising receiving a message from the second apparatus, the message indicating assignment of the first apparatus to the group and indicating, for the group ID, a spatial stream associated with the first apparatus in MU packets to be transmitted to the group from the second apparatus.

28. The method of claim 27 , further comprising decoding the MU packet using the spatial stream associated with the group ID for the first apparatus.

29. The method of claim 27 , further comprising considering the assignment of the first apparatus to the group as being valid for at most a duration of the MU packet or until a gap occurs that is longer than a point coordination function (PCF) interframe space (PIFS).

30. The method of claim 25 , wherein the method further comprises: receiving another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs, wherein the other MU packet is not immediately preceded by another frame with another MAC address; determining that the other MU packet was transmitted by an access point (AP); and interpreting the other group ID as assigned by the AP.

31. The method of claim 25 , wherein the method further comprises: receiving another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs; receiving an indication of a Basic Service Set Identifier (BSSID) in another frame received prior to the other MU packet; and interpreting the other group ID based on the BSSID.

32. A first apparatus for wireless communications, comprising: means for receiving a multi-user (MU) packet from a second apparatus, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the first apparatus belongs and wherein the means for receiving is also configured to receive an indication of a media access control (MAC) address of the second apparatus, wherein the indication of the MAC address of the second apparatus is received in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble; and means for interpreting the group ID based on the MAC address.

33. The first apparatus of claim 32 , wherein the means for interpreting is configured to interpret the group ID by determining that the MAC address is associated with the second apparatus, such that the MU packet was transmitted by the second apparatus and the group ID is associated with the second apparatus.

34. The first apparatus of claim 32 , wherein the means for receiving is configured to receive a message from the second apparatus, the message indicating assignment of the first apparatus to the group and indicating, for the group ID, a spatial stream associated with the first apparatus in MU packets to be transmitted to the group from the second apparatus.

35. The first apparatus of claim 34 , further comprising means for decoding the MU packet using the spatial stream associated with the group ID for the first apparatus.

36. The first apparatus of claim 34 , further comprising means for considering the assignment of the first apparatus to the group as being valid for at most a duration of the MU packet or until a gap occurs that is longer than a point coordination function (PCF) interframe space (PIFS).

37. The first apparatus of claim 32 , wherein the means for receiving is configured to: receive another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs, wherein the other MU packet is not immediately preceded by another frame with another MAC address, and wherein the first apparatus further comprises: means for determining that the other MU packet was transmitted by an access point (AP); and means for interpreting the other group ID as assigned by the AP.

38. The first apparatus of claim 32 , wherein the means for receiving is configured to: receive another MU packet comprising an indication of another group ID indicating another group to which the first apparatus belongs; and receive an indication of a Basic Service Set Identifier (BSSID) in another frame received prior to the other MU packet and wherein the means for interpreting is configured to interpret the other group ID based on the BSSID.

39. A non-transitory computer-readable medium comprising instructions executable to: receive, at a first apparatus, a multi-user (MU) packet from a second apparatus, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the first apparatus belongs; receive an indication of a media access control (MAC) address of the second apparatus, wherein the indication of the MAC address of the second apparatus is received in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble; and interpret the group ID based on the MAC address.

40. A wireless node, comprising: at least one antenna; a receiver configured to: receive, via the at least one antenna, a multi-user (MU) packet from an apparatus, wherein the MU packet comprises an indication of a group identifier (ID) indicating a group to which the wireless node belongs; and receive, via the at least one antenna, an indication of a media access control (MAC) address of the apparatus, wherein the indication of the MAC address of the apparatus is received in a preamble of the MU packet and wherein the indication of the MAC address is located after a very high throughput (VHT) signal A (VHT-SIG-A) field and before training fields in the preamble; and a processing system configured to interpret the group ID based on the MAC address.